BACKGROUND: The purpose of this study was to determine if the routine use of postoperative continuous positive airway pressure (CPAP) in patients undergoing laparoscopic Roux-en-Y gastric bypass (RYGB) is associated with an increase in transmural gastric pouch pressure, which may create the risk for anastomotic leak. METHODS: Transmural gastric pressures (difference between gastric pouch and bladder pressures) were measured postoperatively [post-anesthesia recovery care unit (PACU) arrival (prior to initiation of CPAP), 5 min, 30 min, and PACU discharge] in 28 patients (19 patients used CPAP, 9 patients did not) following laparoscopic RYGB. Changes in pressure over time were assessed using a generalized estimating equation, taking into account the repeated measurements obtained for each subject. In all cases, two-tailed P values ≤0.05 were considered statistically significant. RESULTS: Among patients that used CPAP, there were no changes in transmural pouch pressure from baseline at any point in time (P = 0.628). However, in patients that did not use CPAP, there was a trend towards increased transmural gastric/pouch pressure (P = 0.053), which could be attributed to a transient decrease in bladder pressure at the 5-min measurement interval. CONCLUSIONS: Application of CPAP did not increase transmural gastric pouch pressure in our bariatric patients; therefore, its use in the post-RYGB patients does not pose a risk for pouch distension, which could lead to the disruption of anastomotic integrity.